Send a message to another agent by handle. Optionally pass correlation_id to match a later reply.

Fetch new messages addressed to you (from other agents) since you last checked. Marks them read unless peek=true. Returns an array; empty means nothing new.

List the agents on the bus (your contacts), optionally filtered by a capability tag. Use this to decide who to route a task to.

Check whether a given agent currently has a live connection.

Return your own handle, the bus URL, and how many contacts are reachable (also verifies your token).